插入每條X距離沿着多行在勻稱

Question

如果我有一個多行對象，其中包含許多行的總長度爲50公里（當從原點追蹤），並且我想插入沿多行的每X米（假設100m），每100m返回勻稱點對象，我該如何實現？

這裏是我迄今爲止，但它只返回一個不同點（當我知道它應該返回幾千，如ArcMap中測試）：

points = [] 

for x in range(100,50000,100): 
    x,y = multiline.interpolate(x).xy 
    xy = (x[0],y[0]) 
    points.append(xy) 

trim = list(set(points)) 

而且這裏是修剪包含：

[(-90.5864707030599, 38.4688716729703)] 

如果我打破了多行成單獨的線，我可以得到更多的積分（162），但仍沒有1000，我應該產生：

lines_shape = [] 

# breaking out individual lines into shapely line strings 
for line in multiline: 
    lines_shapes.append(gm.asLineString(line)) 

points = [] 

# interpolating points along each line 
for line in lines_shapes: 
    for x in range(100,50000,100): 
     points.append(line.interpolate(x)) 

point_list = [] 
for point in points: 
    x,y = point.xy 
    xy = (x[0],y[0]) 
    point_list.append(xy) 

trim = list(set(point_list)) 

和裝飾包括：

[(-90.4766827033434, 38.5972414054466), (-90.5461231698478, 38.5000688058116), (-90.4968889030998, 38.5464768729898), (-90.6189469029766, 38.4718782063951), (-90.513144169767, 38.5129150061034), (-90.5810937033111, 38.5323612724354), (-90.5396967035394, 38.5864442726652), (-90.6868857696619, 38.447798672452), (-90.6213193028429, 38.5146844725911), (-90.509758103553, 38.5536796727591), (-90.476078103521, 38.546296205486), (-90.6427893693333, 38.5555682724382), (-90.6217561026614, 38.5147302723649), (-90.630436369842, 38.5000560723107), (-90.4760629697296, 38.5914768059899), (-90.6849423697939, 38.4566312056467), (-90.6538383698443, 38.4599348058277), (-90.4699029698455, 38.5837950057152), (-90.6694679700701, 38.4474470726055), (-90.6829395031549, 38.4198408724397), (-90.6732927030951, 38.4360894058827), (-90.5866617028747, 38.5332390062557), (-90.6961129028875, 38.4531938061303), (-90.5947731029956, 38.4539120730648), (-90.5142317702794, 38.5249724721824), (-90.5903123694197, 38.5034458725098), (-90.5755567699284, 38.5000690063604), (-90.56752770364, 38.5589170059954), (-90.6271141698824, 38.5430544723665), (-90.6201437702182, 38.4550620064875), (-90.6180047030539, 38.5000570723568), (-90.6589975699812, 38.500065872223), (-90.685946302779, 38.4505508056563), (-90.6840849030951, 38.4547842059075), (-90.6854941029699, 38.4134104059469), (-90.5918703027716, 38.5000662058715), (-90.5471115031927, 38.4808140060424), (-90.463451370184, 38.5525954725834), (-90.6780159694608, 38.4460308724081), (-90.5896267029094, 38.5346980060887), (-90.5807949701111, 38.5325790054973), (-90.7004947695174, 38.4727768728354), (-90.5955769035506, 38.5373834725497), (-90.6569789697031, 38.4542776061077), (-90.6253669031594, 38.521868606032), (-90.6565429028321, 38.4538942062337), (-90.4636589696851, 38.552869806277), (-90.634338969767, 38.546211672811), (-90.4360581033981, 38.5162080059754), (-90.478937169714, 38.604583072231), (-90.6238845029668, 38.5403794056656), (-90.5115069701699, 38.5170084061937), (-90.6607629031848, 38.4788458064697), (-90.6182993029698, 38.4996076730365), (-90.6795531698423, 38.4464060057138), (-90.5715115033526, 38.5319224725247), (-90.6601255698386, 38.4660196727507), (-90.5944027028219, 38.4399328061353), (-90.6658113032484, 38.5630904727274), (-90.657297702926, 38.4486316730944), (-90.6076871697265, 38.5411054058703), (-90.5189131030566, 38.4958198724699), (-90.4633435036991, 38.5571938060298), (-90.4550633700778, 38.5794588057595), (-90.6551231026484, 38.5026692062996), (-90.6304847695558, 38.4814012057819), (-90.6293281694588, 38.5510622058365), (-90.5337045036593, 38.5480590727484), (-90.5636725699325, 38.5031146728847), (-90.5893179035978, 38.5349642063136), (-90.5502847700255, 38.5531414725813), (-90.6577657029242, 38.4673132728702), (-90.6842995029191, 38.45499127301), (-90.596995102941, 38.536759005804), (-90.4590855033927, 38.579707805551), (-90.618116169525, 38.5138608060121), (-90.662823570151, 38.4436198061903), (-90.5324573031614, 38.5290608063917), (-90.4761187699646, 38.5460198060497), (-90.4365065035716, 38.5163978060946), (-90.5993421032549, 38.4517628723399), (-90.6580597695421, 38.4672556730918), (-90.4697125698785, 38.5713498724789), (-90.6246789694582, 38.5225716726252), (-90.5623807028065, 38.539724406037), (-90.5255411029389, 38.5592538722488), (-90.6779729027267, 38.4309624725214), (-90.5757351702413, 38.5712982055281), (-90.4349003036055, 38.5470764060318), (-90.4881969699136, 38.5968882057062), (-90.5654833701608, 38.5641550721791), (-90.6243467697869, 38.5407896062358), (-90.6833993696845, 38.4554192064123), (-90.5125843031225, 38.5353802722622), (-90.4343933036075, 38.5320694055591), (-90.5949243033133, 38.4437996058484), (-90.6531879693487, 38.5465062727268), (-90.4678253704438, 38.5769334060321), (-90.6560765692776, 38.4512860059256), (-90.6705015033411, 38.4387672065226), (-90.4510205703424, 38.5293378056758), (-90.5965189694742, 38.453478006286), (-90.5158851037139, 38.5293438059525), (-90.5153219032826, 38.5000608728918), (-90.571685370183, 38.5322450728324), (-90.5907731028958, 38.5035282063425), (-90.562387970228, 38.5396736725824), (-90.5632127699527, 38.5000698058576), (-90.4351277034801, 38.5467304062636), (-90.6846297033974, 38.4247822729648), (-90.4300920979354, 38.5121736658553), (-90.6077071031996, 38.5414430059705), (-90.700472969951, 38.4725166728872), (-90.6083531698623, 38.5440140058222), (-90.6611483697009, 38.478763472637), (-90.5148001696915, 38.5340326723505), (-90.6261891029441, 38.4987850056043), (-90.6077131034763, 38.5415200724739), (-90.5714903701838, 38.5588274721905), (-90.487086969987, 38.5953794059149), (-90.6309363029674, 38.4813284731115), (-90.4375485030603, 38.5798804061361), (-90.4348689037762, 38.5318386727971), (-90.4636395029601, 38.5528440056267), (-90.5537693695601, 38.5918534726398), (-90.686189369743, 38.45065887269), (-90.5137219032426, 38.5459956061927), (-90.4708333032137, 38.5588582056221), (-90.562663570167, 38.5400910056759), (-90.5898827695735, 38.4573650056716), (-90.6541333699584, 38.4598728056666), (-90.5201981695093, 38.5275174726339), (-90.5279559031418, 38.5197458058049), (-90.4969485029704, 38.5468012728409), (-90.6963449693442, 38.4523242057786), (-90.5869187695849, 38.5329812056987), (-90.7090465028932, 38.4391836726696), (-90.4722723695735, 38.5676876055788), (-90.6076811029, 38.541104472374), (-90.6281757035453, 38.4421816724275), (-90.5341799698291, 38.5482110060135), (-90.5948001033415, 38.494925272764), (-90.5864707030599, 38.4688716729703), (-90.5419337032772, 38.5685326058754), (-90.7019565698392, 38.4481112057488), (-90.6253121695204, 38.521868606032), (-90.5138205031131, 38.5456764727715), (-90.5529913031055, 38.455285806376), (-90.32933, 38.5986526054135), (-90.6309013697018, 38.5463032723585), (-90.4975365696563, 38.6037882720911), (-90.6184813032689, 38.4720362730366), (-90.6781275699308, 38.4462692727899), (-90.5651579702635, 38.4796824727488), (-90.6532305027848, 38.5024180058671), (-90.6545907030978, 38.5581974062657), (-90.5950401027179, 38.4950944055632), (-90.6468105700511, 38.5573522728695), (-90.6698367029009, 38.4476676727061), (-90.4501431701705, 38.5848148728883), (-90.577996903134, 38.503304272455), (-90.6713375697724, 38.545723072942)] 

也許這個問題是在我傳遞插值的說法？我怎麼知道它期望/假設距離在哪個單位？

編輯：多行的

定義 - 這個代碼打開了一個JSON文件GeoJSON的要素集合對象，然後拿出具體的GeoJSON的MULTILINESTRING並將其轉換成一個身材勻稱MULTILINESTRING對象。

from shapely import geometry as gm 
import json 

file = 'Geometries_GEOJSON.json' 

with open(file) as input_file: 
    data = json.load(input_file) 

geojson_multilines = data['features'][1]['geometry'] 

multiline = gm.shape(geojson_multilines) 

這裏是什麼樣子：

轉換之前，作爲以GeoJSON對象：

{u'type': u'MultiLineString', u'coordinates': [[[-90.4360581033981, 38.5162080059754], [-90.4356193034874, 38.5151156723311], [-90.4349665036006, 38.5145500059587], [-90.4312643032044, 38.5129080723304], [-90.4300920979354, 38.5121736658553]], [[-90.4348689037762, 38.5318386727971], [-90.4353155700569, 38.5236814729023], [-90.4360581033981, 38.5162080059754]]....... 

轉換後，作爲以GeoJSON對象：

MULTILINESTRING ((-90.4360581033981 38.5162080059754, -90.4356193034874 38.5151156723311, -90.43496650360061 38.5145500059587, -90.4312643032044 38.5129080723304, -90.4300920979354 38.5121736658553), (-90.43486890377621 38.5318386727971, -90.4353155700569 38.5236814729023, -90.4360581033981 38.5162080059754),........ 

一個例子在ArcMap中映射的一個對象：

Answer 1

在你的第一個代碼片段中，你正在迭代150米乘150米，但你的數據集似乎在經度 - 緯度。您應該以米爲單位對其進行重新投影（在適合您所在區域的CRS中），因爲它們在物體單位中的參數爲distance。 爲例從shapely documentation採取：

from functools import partial 
import pyproj 

project = partial(
    pyproj.transform, 
    pyproj.Proj(init=’espg:4326’), 
    pyproj.Proj(init=’epsg:26913’)) # Replace by the appropriate CRS 
g2 = transform(project, g1) # g1 is a shapely geometry 

您還可以通過在interpolate功能使用標準化值避免轉型：

# Progress of 10% of the length: 
line.interpolate(0.10, normalized=True) 

Answer 2

由於@mgc指出，必須項目中的數據到具有以米爲單位的距離單位的笛卡爾座標參考系統。

我使用一個函數來重新分配頂點，它使用interpolate線性引用方法。距離參數僅爲近似值，因爲線串的總距離可能不是優選距離的倍數。此功能僅適用於[Multi] LineString幾何類型。

from shapely import wkt 
from shapely.geometry import LineString 

def redistribute_vertices(geom, distance): 
    if geom.geom_type == 'LineString': 
     num_vert = int(round(geom.length/distance)) 
     if num_vert == 0: 
      num_vert = 1 
     return LineString(
      [geom.interpolate(float(n)/num_vert, normalized=True) 
      for n in range(num_vert + 1)]) 
    elif geom.geom_type == 'MultiLineString': 
     parts = [redistribute_vertices(part, distance) 
       for part in geom] 
     return type(geom)([p for p in parts if not p.is_empty]) 
    else: 
     raise ValueError('unhandled geometry %s', (geom.geom_type,)) 

# E.g., every 100 m on a projected MultiLineString 
multiline_r = redistribute_vertices(multiline, 100)